Heating system



March 4, 1941.

G. R. RADLEY HEATING SYSTEM Filed Sept. 24, 1937 INVENT OR. 601 A?Papzzy Z2, 2d

TTORNEY.

Patented Mar. 4, 1941 warren stares HEATING SYSTEM Application September241, 1937, Serial No. 165,457

Claims.

This invention relates to a heating system and is particularly directedto a control for such system.

Objects of this invention are to provide a novel form of heating systemin which the main-control is located in a return duct for the air orother fluid, in which a substantially instantane ous response to anyvariation in the temperature of the returning air. is secured in whichovershooting of the furnace is avoided, in which the safe temperature ofthe furnace is never exceeded, in which the flame in the furnace isproportioned to the demand in an immediate and substantially exactmanner, in which coml5 pensation for variation in outside temperature isprovided, and in which the system is so arranged that when a door orwindow is opened or when a register in any room is opened or closed, asubstantially instantaneous adjustment is made prior to altering theaverage temperature of the entire air in the building.

Further objects are to provide a remote control which although operatedfrom a room in the building, nevertheless controls the main con- 25 trolmember and in efiect alters its adjustment so that the temperature ofthe returning air at which it works may be either raised or loweredbefore a response from this control member is obtained.

Further objects are to provide a remote control which has a dayadjustment and a night adjustment, which has a clock that automaticallythrows in the day or night adjusting means, and which has a thermostatwhich will alter the effective adjustment of the main control member.

Itv is well' known that in spite of all of the adjustments that may bemade lnteriorly of a' building in an attempt to approach satisfactoryautomatic temperature control, that nevertheless variations in theoutside temperature materially alter the effectiveness of the automaticcontrol system.

This invention is designed to provide, in addition to the featuresherelnabove enumerated, a

45 further remote control for the main control member so that automaticadjustment is made for variations in the outside temperature. Forexample, if the outside temperature should rise,

this change is automatically compensated for so by lowering the requiredtemperature at which the automatic control member will respond and, onthe other hand, if the temperature should drop outside of thebuilding,the effect of the main control member is automatlcallyaltered 115 sothat it will respond only to higher temperatures of air in the returnduct, thereby providing an automatic compensation for variations in theoutside temperature.

In greater detail, this invention contemplates a novel form of remotecontrol which operates 5 by adding an amount of heat to a thermostaticcontrol member, such amount of heat being additional to that picked upby the control member from the air or other heating medium acting on thecontrol member, the automatic control 10 being adjustable to increase.or decrease this added-amount of heat to thereby alter the point atwhich the thermostatic control member will respond, the inventioncontemplating a highly flexible system of remote control so that theamount of added heat may be increased or decreased either manually orautomatically and so that compensation for variation in the outsidetemperature may be additionally obtalnedl' Embodiments of the inventionare shown in the accompanying drawing, in which: i;

Figure l. is adlagrammatic view showing a fragment of a house with theburner and control systeminstalled, parts being brolsen away andinsection. ii Figure 2 is a wirin control system.

Figure 3 is a fragmentary view form of the invention.

diagram of the rembte of a further Figure 4 is a fragmentary view of a.modified form of an external control unit adapted to be locatedexternally of the building. 3

Referring to Figure 1, it will be seen that, a. fragment of a buildinghas been indicated and that although one room only has been shown. it isintended that as many rooms as desired may be furnished from thefurnace. One of the liot air outlets is indicated by the referencechairacter I and one of the cold air returns by the reference character2. The main cold air return is indicated at 3 and the furnace isindicated at 4. This furnace is provided with a combustion chamber inwhich are located preferably a plurality of burners indicated at 5, eachbeing provided with by the by-pass pllot line 6 and controlled by thevalve 1, the main gas line being indicated by the reference cha'racer 8.A pressure reducing valve 9 and an automatically controlled valve l0 anda manually operable cut-of! valve II are pro- 50 vided in the main gasline to the burners.

The automatically controlled valve Ill may be either a. modulating valveor an on and oi! valve and is preferably of the diaphragm control type,

-or, in other words, 'a fluid relay means con- 5 an individual pilotlight furnished trolling the main valve, though any other suitable motormeans could be employed without departing from the spirit of thisinvention. If

the valve is an on and ofi type, it cuts on and off fully in a wellknown manner and has no intermediate position. On the other hand, if athrottling or-fioating type of valve is employed, the valveautomatically adjusts itself to the re- "quirements, the invention inits broadest aspect being applicable to either type of valve.

the valve IIl being a gas controlled automatic valve either of the onand oil type or of the modulating type.

The main control member I2 is the ordinary type of throttling thermostatwhich throttles the amount of gas or other fluid that may be passedtherethrough as the temperature ofthe thermo-.

from the bleed line stat rises.

The valve III is controlled by the escape of gas I4. As the gas escapesfrom this bleed line, the valve I0 opens. When no gas escapes from thebleed line I4, thevalve closes. The bleed line II passes through thethermostat I3 which is a limit thermostat located in the bonnet of thefurnace and through the thermostat I2, to the exhaust pipe I5. If eitherof the thermostats I2 or. I3 close the bleed line, the valve III willclose. The thermostat I3 operates as a limit control so that if thefurnace gets too hot irrespective of'the operation of any other portionof the apparatus, the thermostat I3 will close the bleed line I4 andcause the valve III to close. Ordinarily the take charge of the valve I0unless the furnace temperatureis too high. Instead the thermostat I2normally has direct control of the valve I II as the thermostat I 3normally remains open.

A remote control unit is indicated by therefer'ence character I 6 and islocated at any suitable place in the building, preferably in the mainroom. An auxiliary remote control unit I1 is located externally of thebuilding and is responsive to outside temperature. This unit preferablyincludes a polished casing so as to reflect radiant energy, such assunshine or radiant heat,

but is responsive to the temperature of the ex- ,ternal air.

Referring to Figure 2, it will be seen that the remote control member I8consists of a manually adjustable rheostat I8 adapted for nighttemperature setting and a manually adjustable rheostat I9 adapted forday temperature setting.

These rheostatsmay each have an 011 point though it is only necessary tohave an off point for the day rheostat indicated generally at I9, suchopen point or ofl point being represented by the reference character 20.When it is desired to cause a very quick response from the furnace, therheostat I9 may be turned to the off point 20 so that the heatingcircuit is open. The entire with. the rheostats I8 thermostatindicatedgenerally at 24 is bridged. around certain of the thermostatic memberthermostat I3 does not readily accomplished stat I9 lessens the amountand are preferably provided with graduations,'as indicated in Figure 2,so that the temperature setting may be marked thereon. A clock 2I isprovided with a switch 22 which shorts out the day rheostat during thenight period and again opens in the morning and places the day rheostatin series with the night rheostat, as shown. If desired an extraresistance may be a fixed resistor,

and I9. Additionally, a

resistance members. For instance, as shown in Figure 2, it is bridgedaround the elements 23 and I8, though it may be obviously bridged aroundthe elements I8, 23 and I9 if so desired, the idea being that when thecloses due to an increase of temperature above a predetermined point,that it will short out the resistance and provide for an increase incurrent flow in the circuit controlled thereby.

The externally located control member is pro vided with a resistor 25which is shorted out by a thermostatically responsive member, forinstance of the Sylphon bellows type as indicated at 26. The Sylphonbellows expands when the temperature rises to a predetermined point andshorts out the resistance 25, thus increasing the current flow in thecircuit controlled by these various resistance elements. Current forthis circuit is furnished. by a simple step down transformer 21 and thecircuit includes a heating element, for instance the heating coil 28, inthermal relation to the main control member I2. The circuit is a lowvoltage circuit and very little energy is required for such controlcircuit. In an actual embodiment of the invention only a few watts arerequired. It is obvious that the heating element 28 may be locatedeither interiorly or exteriorly of'the return duct 3, it having beenshown as exteriorly located in Figure 2 and interlorly located in Figure3, such latter figure being hereinafter described.

The operation of the apparatus is as follows If it is desired to raisethe temperature setting or effective point at'which the mainthei'mostatic member I2 will respond, it is obvious'that the additionalamount of heat supplied by the heating element 28 must be decreased.This is y rheostat I9 for instance, thereby determining the particulartemperature at which the system will respond for the day setting.

Obviously the increased resistance of the rheoof current flowing in theheating element 28 and consequently decreases the amount of'additionalheat furnished the control member I2. therefore, will adjust the valveI0 so that the furnace supplies an .increased amount of heat until thereis again a. suitable balance established at which the thermostat I2responds, the thermostat I2 responding to the sum of the two amounts ofheat, namely, that due to the heat in the re-' turn duct 3 and that dueto the heatfurnished by the heating element 28.

On the other hand, if less heat is required, the rheostat I9 may haveits resistance dec'reased, thus increasing the amount of heatadditionally supplied the thermostat I2 by the heating element 28. Thetemperature in the duct 3 can fall therefore and a lower temperaturewill be required and less heat will be furnished by the furnace. 4 \gObviously the night setting is obtained in ex,-

manually adjusting the element 23, which may be provided in series Thecontrol member,.

actly the same manner by adjusting the rheostat l8.

When the clock 2| shorts out the day rheostat l9, there is lessresistance in this control circuit and consequently more additional heatis furnished the thermostat l2 by the heating element 28 and a lowertemperature in the house then obtains.

The purpose of the thermostat 24, which closes with an increasingtemperature and opens with a decreasing temperature, is to short out amaterial portion of the resistance in the control circuit, thusmaterially increasing the amount of additional heat furnished thethermostatic member l2, thereby insuring a relatively quick response tothus prevent any chance of overheating and to minimize the amount ofovershooting of the furnace. It is clear that when a material amount ofthe resistance is cut out of the control circuit, that a quick responseis obtained.

The outside control unitll cuts out the resistance if the externaltemperature rises beyond a predetermined point for which the unit isset. This decreases the resistance in the control circuit andconsequently causes an increase in the amount of heat added to thethermostat l2 and thus lessens theamount of heat furnished by thefurnace. It is clear, therefore, that an additional automatic remotecontrol is provided which functions in accordance with variations in theexternal temperature.

It is preferable to mount the control unit l6 at a height approximatingthat of the head of an individual when standing so as to secure aresponse of the thermostat 24 if the temperature should rise above apredetermined point at this level prior to any rise in occur in thereturn duct 3, thus materially reducing the amountof overshooting of thefurnace.

It is obvious have to be a fixed resistance. For example, a rheostat 29,as shown in Fig. 4, may be provided and the movable arm thereof may beoperated from the Sylphon bellows 30 corresponding to the member 26previously described. In this manner the amount of resistance isdecreased proportionately to the increase in the external temperatureinstead of cutting out and in a fixed amount of resistance. When thetemperature rises, the amount of resistance is decreased automaticallyby the motion of the thermostatic member or Sylphon bellows member 30.

. It is obvious that other forms of control could be used from thatshown. The form chosen for illustration is a preferred form but is notintended in any way as limiting the scope of the invention. For thispurpose one additional form has been illustrated in Figure 3, thoughobvious- 1y other forms of control, as stated, could be employed. Inthis form of the invention the main control member 3|, which is mountedin the cold air return duct 3, may, through a multiplying leverarrangement, operate the control shifting lever 32. This lever may beconnected by chains 33 and 34 with the damper 35 in the smoke pipe andwith the air inlet 36 for the combustion chamber of the furnace. Thistype of control would be suitable for a viously if other forms of fuelwere used, other types of furnace control members would be employed inplace of the valve l0 provided the furnace control was from the mainthermostatic control member 12 which was remotely controlled ashereinabove described.

temperature that may that the resistance 25 does not.

coal-fired furnace. Ob-' a circulating medium,

burner and having an outlet and an inlet for I It is to be understoodthat in the form of the invention shown in Figure 1, that the controlmembers I2 and i3 are in reality gas thermostats and control the bleedline H from the valve l0 to thus control the operation of this automaticvalve.

It will be seen that although the main control is located in the coldair return duct, that nevertheless remote control is provided and thatthe remote control is such that it may be set for any degree of night orday temperature and that a limit thermostat is provided with this remotecontrol unit and clock for night and day operation. Also it will be seenthat automatic remote control has been provided which proportions thesystem to the external temperature.

It is to be noted furtherthat the entire device is very simple andpractical and may be easily installed without requiring any elaborateprecautions to be taken as the system is primarily a low voltage system.The parts composing the control system are relatively simple andinexpensive.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

I claim:

1. In a hot air system, a furnace having a cold air return and a hot airoutlet, a fuel burner for said furnace, a valve controlling said burner,thermally responsive main control means located in the cold air returnfor controlling said valve in accordance with the temperature of thecold air return to said furnace, a heating element for adding additionalheat to said main control means to shift the point of calibration ofsaid main control means, a source of electric energy for supplying saidheating element, a pair of rheostats for controlling the amount ofelectrical energy supplied said heating element, and clock means forcutting out one of said rheostats.

2. In a heating system, a. furnace for heating a circulating medium,such furnace having an outlet pipe and a return pipe, a throttlingthermostatically responsive main control means located in said returnpipe, a burner, fluid relay means for operating the control valve andfor said furnace, a control valve for said burner having a bleeder lineleading to and controlled by said throttling thermostatically,responsivemain control means, an electrical heating unit for adding heat to saidmain control means, a source of electrical energy for supplying saidheating unit, and a'manually adjustable rheostat located at a pointremote from said main control means for controlling the amo t ofelectrical energy Supplied to said heating-unit.

3. In a heating'system, heating means including a gas burner, athermostatically responsive modulating control means, a modulatingcontrol valve for said burner, fluid relay means for operating themodulating control valve and having a bleeder line leading to andcontrolled by said thermostatically responsive modulating control means,an electrical heating unit for adding heat to said modulating controlmeans, a source of electrical energy for supplying said heating unit,and temperature responsive means for controlling the supply ofelectrical energy to said heating unit.

4.. In a heating system, a furnace for heating said furnace having asaid medium, a temperature responsive modu- 7-:

4 lating control means acted upon by said medium, a control valve forsaid burner for controlling the flow of fuel to said burner, fluid relaymeans for operating said control valve, means operatively connectingsaid temperature responsive modulating controlmeans with said fluidrelay means for controlling the pressure acting on said fluid relaymeans by said temperature responsive modulating control means, anelectrical heating unit for adding heat to said temperature responsivemodulating control means to change the point at which it will respond tothe ambient temperature, a source of electrical energy for supplyingsaid electrical heating unit, and temperature responsive means forcontrolling the supply of electrical energy to said electrical heatingunit.

5. In a heating system, a furnace for heating a circulating medium, saidfurnace having a burner and having an outlet and an inlet for saidmedium, a temperature responsive modulating modulating control means tochange the point at which it will respond to the ambient temperature, asource of electrical energy for supplying said electrical heatingunit,'temperature responsive means for controlling the supply ofelectrical energy to said electrical heating unit, and manuallyadjustable means for adjusting the amount of heat supplied said heatingunit.

GUY R. RADLEY.

